rationalskepticism.org

ughaibu wrote:

zoon wrote:

ughaibu wrote:1. that there are some laws of chemistry and physics which, together with a relevant description of the brain and its environment, mathematically entail all future human behaviour [ ]
If we assume that the first claim is true, then there is a time one at which the description and the laws mathematically entail all the future behaviour of two humans A and B. At time two A says "heads you buy, tails I do" and B agrees, at time three A tosses a coin that lands tails up and at time four A buys the drinks for both of them. This is an everyday situation that I'm sure any reader has been in at some time, so you know this behaviour is unproblematically possible, but more to the point, it is another example of a procedure for recording an observation, so it is required by our ability to do science that we can behave like this. In short, if we have the experimental apparatus, in this case a standard coin, and we have the recording equipment, in this case someone selling drinks and enough money to buy a round, then either science is impossible or we can toss the coin and record the result by one of us buying the drinks.

In the scenario you describe above, the people concerned are using our evolved folk psychology (or Theory of Mind), not science, to predict and control each other.

This is explicitly not the case.
I have assumed that there are laws of chemistry/physics which, given the initial conditions of any universe of interest, exactly entail all the subsequent behaviour of the human beings in that universe of interest. Thus the assertion "heads you buy, tails I do" is entailed by the laws, the action of tossing the coin and its result are entailed by the laws, and the act of buying the drinks is entailed by the laws.
The only other assumption is that science requires that researchers can reliably record their observations.
This means that at time three, when A and B observe that the result of tossing the coin is tails, they know, because their recording procedure has been defined by them as "heads you buy, tails I do", that if they have the ability to do science, then it is logically entailed that at time four A will buy the drinks. As, by assumption, it is also the case that there are laws that mathematically entail that at time four A will buy, they have successfully solved the problem of calculating what is entailed by the laws.